Aisin Seiki Kabushiki Kaisha

Advics Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Satoshi Ishida

Michiharu Nishii

Akihito Kusano

Masaki Oishi

Masahiko Kato

Takashi Kurokawa

Kyousuke Hata

Shota Murai

Taito Goto

Toshio Sugimura

Kenji Tozu

Kiyoyuki Uchida

Kazuya Maki

Akira Sakai

Tatsuo Sugitani

Masaaki Uechi

Yasunori Sakata

Hiroshi Ueno

Genji Mizuno

Masayuki Arai

Tatsuya Kawamura

Tetsuya Kuno

Kazutaka Noro

Ryohei Yuasa

Yoshinori Suzuki

Hideo Mizukoshi

A four-wheel drive vehicle in which, when a switching request is made for switching from a non-meshing state to a meshing state, the control device calculates a first rotation speed difference between the drive-power-source-side meshing teeth and the sub-drive-wheel-side meshing teeth, and a second rotation speed difference between the drive-power-source-side meshing teeth and the sub-drive-wheel-side meshing teeth. If at least one of the calculated first and second rotation speed differences is within a predetermined range set in advance, the control device couples the sub-drive wheel corresponding to the rotation speed difference within the predetermined range, to the central axle by the control coupling to switch the dog clutch from the non-meshing state to the meshing state. And, if neither the calculated first nor second rotation speed difference is within the predetermined range, the control device prohibits switching of the dog clutch from the non-meshing state to the meshing state.

Four-wheel drive vehicle

An electronic control unit executes gradual reduction control when a friction clutch is to be maintained in a fully engaged state such that an input rotary member and an output rotary member rotate integrally. As a result, a motor current supplied to a motor is adjusted to a lower current value. Thus, an average current value of the motor current supplied to the motor when the friction clutch is to be maintained in the fully engaged state is appropriately reduced.

Power transfer device for vehicle and control method of power transfer device

A fluid-pressure brake device for a vehicle includes a brake operation member, a master cylinder, wheel cylinders a fluid-pressure control actuator, a fluid-pressure control circuit, and an electric control unit. Moreover, in the fluid-pressure brake device for a vehicle, normally closed electromagnetic open/close valves are interposed on paths for connecting master system fluid-pressure circuits and a drive fluid chamber of the master cylinder with each other, the master system fluid-pressure circuits being configured to connect pressure chambers of the master cylinder and pressure chambers of the wheel cylinders&#x2014;with each other. The fluid-pressure brake device for a vehicle is configured so that the electromagnetic open/close valves are opened when an action amount of the brake operation member is equal to or more than a set value. As a result, a size and a stroke of each of master pistons in the master cylinder can be reduced.

Fluid-pressure brake device for vehicle

A brake device includes: a mechanical pressure regulating part having a high-pressure port, a low-pressure port, a pilot pressure input port, and an output port which outputs fluid pressure corresponding to the pressure supplied to the pilot pressure input port by fluid pressures supplied to both of the high- and low-pressure ports, to a chamber for a master piston; a high-pressure source connected to the high-pressure port and the pilot pressure input port; a low-pressure source connected to the low-pressure port and the pilot pressure input port; and an electrically-operated pilot pressure generating part which includes control valves for controlling flows of the brake fluid between the high-pressure source and the pilot pressure input port, and between the low-pressure source and the pilot pressure input port, respectively, and which outputs desired fluid pressure to the pilot pressure input port by controlling flow of the brake fluid with control valves.

Brake device

A master cylinder device including: a housing whose front side is closed and which has a separation wall for separating the inside of the housing into a front side chamber and a rear side chamber; a pressurizing piston disposed in the front side chamber so as to define a pressurizing chamber for pressurizing the brake fluid and an input chamber into which a brake fluid from a high pressure source is introduced; an input piston disposed in the rear side chamber and moving forward by an operation force; and a transmission rod which is through the separation wall, whose proximal end portion is fixed in one of the pressurizing and input pistons, and whose distal end portion is apart from the other of the pressurizing and input pistons in a state of no forward movement.

Master cylinder device

A vehicle brake device is provided with a master piston which is driven to generate a master cylinder pressure. The device includes a pressure accumulation portion that accumulates the brake fluid under pressure; a servo pressure generation portion that is configured to be able to generate the servo pressure using the brake fluid in the pressure accumulation portion regardless of the operation of the brake operation member; brake fluid consumption correlative value detection means for detecting a brake fluid consumption correlative value relating to a consumption of the brake fluid in the pressure accumulation portion; and failure detection means for driving the master pistons only by the servo pressure using the servo pressure generation portion in a state where the brake operation member is not operated, and detecting a failure of a master system, based on a brake fluid consumption correlative value detected by the brake fluid consumption correlative value detection means at that time.

Vehicle brake device

A braking device comprises: a master cylinder; an electrical pressure adjusting unit; a reaction force generating unit, which forms a reaction force chamber and which generate a reaction hydraulic pressure in the reaction force chamber; a reservoir for brake fluid; an inter-chamber brake fluid path; a reservoir path that connects the reservoir and the inter-chamber brake fluid path; and a normally-closed control valve, wherein the electrical pressure adjusting unit includes an electrical pump which is directly connected with the driving hydraulic pressure chamber to supply the brake fluid to the driving hydraulic pressure chamber, and wherein at least one of electromagnetic valves provided in the electrical pressure adjusting unit and the reaction force generating unit is a normally-opened electromagnetic valve, which is provided in the inter-chamber brake fluid path and is configured to communicate the inter-chamber brake fluid path in a non-conduction state.

Braking device

A brake device can prevent deterioration of braking force by applying a predetermined pressure in the drive hydraulic pressure chamber even when an electric system failure occurs. The brake device includes a stroke simulator portion, regulator, a first passage connecting the accumulator and the high pressure port of the regulator, a second passage connecting the reservoir tank and the low pressure port of the regulator, a third passage connecting the stroke simulator portion and the pilot pressure input port of the regulator, a fourth passage connecting the drive hydraulic pressure chamber and the output port of the regulator and a fifth passage connecting the accumulator and the drive hydraulic pressure chamber bypassing the high pressure port. The normally open type pressure decrease control valve is provided in the second passage or in the fourth passage whereas the normally closed pressure increase control valve is provided in the fifth passage.

A brake apparatus includes: a master cylinder that forms a driving fluid pressure chamber, which drives master pistons as brake fluid is supplied and discharged; a pressure adjusting part adjusting a driving fluid pressure of the driving fluid pressure chamber; a reaction force generator that forms a reaction force chamber and that is configured to generate a reaction force fluid pressure in the reaction force chamber in accordance with an operating amount of the brake operation member; a brake fluid path, which connects the reaction force chamber to the driving fluid pressure chamber, and a valve device configured to block, at a current-on state, flowing of the brake fluid, and that communicates, at a current-off state, the reaction force chamber to the driving fluid pressure chamber through the brake fluid path to enable the flowing of the brake fluid.

Brake apparatus

An ECU executes a program that includes the steps of setting a line pressure to a line pressure () that is appropriate for improving fuel efficiency, if an automatic transmission is not shifting, and a deceleration slip control for a lock-up clutch is not being executed; setting the line pressure to a line pressure () that is equal to or lower than a line pressure () that is appropriate when the automatic transmission is shifting, if it is determined that the automatic transmission is not shifting, and the deceleration slip control is being executed; and setting the line pressure to the line pressure (), if it is determined that the automatic transmission is shifting. The line pressure () is lower than the line pressure (). The line pressure () is equal to or lower than the line pressure ().

Line pressure control apparatus and line pressure control method for automatic transmission

A hydraulic brake device includes a hydraulic pressure supply passage for reducing the output hydraulic pressure by a first proportional solenoid valve and supplying it to a hydraulic passage leading from a pressure adjusting valve to the wheel cylinders, a second proportional solenoid valve disposed between the hydraulic pressure supply passage and the pressure adjusting valve for reducing the hydraulic pressure supplied from the hydraulic pressure supply passage, and a check valve parallel to the second proportional solenoid valve. Hydraulic pressure control during automatic brake control is carried out by the first and second proportional solenoid valves. When the brake pedal is operated during automatic brake control and output hydraulic pressure of the pressure adjusting valve exceeds hydraulic pressure in the hydraulic pressure supply passage by automatic brake control, the output hydraulic pressure of the pressure adjusting valve flows toward the hydraulic pressure supply passage through the check valve.

Vehicle hydraulic brake device

A hydraulic braking pressure generating apparatus for a vehicle includes a hydraulic pressure generator for generating a predetermined hydraulic pressure irrespective of a braking operation of a brake operation member and for outputting the predetermined hydraulic pressure, an input member moved in response to the brake operation member, a first elastic member for transmitting a brake operation force applied to the input member and for applying a stroke corresponding to the brake operation force to the input member, a regulation valve connecting to the first elastic member and for regulating the outputted hydraulic pressure of the hydraulic pressure generator in response to the brake operation force transmitted through the first elastic member and for outputting a regulated hydraulic pressure and a second elastic member connecting the regulation valve and for urging the regulation valve toward its initial position. A mounting load of the first elastic member is set larger than a mounting load of the second elastic member.

Hydraulic braking pressure generating apparatus for a vehicle and a hydraulic brake device for a vehicle including a hydraulic braking pressure generating apparatus

The present invention is directed to a master cylinder provided with an annular seal member (S) having an annular groove of U-shaped cross section formed on its one end face, and a substantially annular seal retainer () for restricting at least axial movement of the seal member, and including a substantially annular lifted wall portion () formed to extend axially into the U-shaped annular groove of the seal member, and a substantially annular step portion () formed on an inner periphery of the lifted wall portion, for contacting an open end face of the seal member. The seal retainer is reduced in diameter by radial pressing force produced when it is received in a cylinder bore (), and restored when the pressing force is released. The seal member is placed in an annular hold groove (), and the seal retainer is received from an open end of the cylinder bore to be placed in an annular transfer groove (), with the seal retainer reduced in diameter. Then, the seal retainer is transferred from the annular transfer groove to an annular hold groove (), and the seal retainer is restored in such a state that the lifted wall portion extends into the U-shaped annular groove of the seal member.

Master cylinder having a seal retainer

A vehicle brake apparatus comprises brake operation detecting device for detecting an operation of a brake operating member, a fluid pressure type booster which boosts the operating force applied to the brake operating member, a pressure detecting device for detecting a pressure supplied to the fluid pressure type booster, and an electric motor control device. A recirculating type hydraulic pressure modulator is disposed in a hydraulic pressure conduit between a master cylinder and a wheel brake cylinder. The electric motor control device drives an electric motor for activating a recirculating pump in response to the brake operation detected by the brake operation detecting device and the pressure detected by the pressure detecting means so that the pressure in the wheel brake cylinder is modulated.

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Chiryu, Japan

Satoshi Ishida